The OpenVPN executable should be installed on both server and client machines, since the single executable provides both client and server functions.

Linux Notes (using RPM package)

If you are using a Linux distribution which supports RPM packages (SuSE, Fedora, Redhat, etc.), it’s best to install using this mechanism. The easiest method is to find an existing binary RPM file for your distribution. You can also build your own binary RPM file:

rpmbuild -tb openvpn-[version].tar.gz

Once you have the .rpm file, you can install it with the usual

rpm -ivh openvpn-[details].rpm

or upgrade an existing installation with

rpm -Uvh openvpn-[details].rpm

Installing OpenVPN from a binary RPM package has these dependencies:

openssl

lzo

pam

Furthermore, if you are building your own binary RPM package, there are several additional dependencies:

openssl-devel

lzo-devel

pam-devel

See the openvpn.spec file for additional notes on building an RPM package for Red Hat Linux 9 or building with reduced dependencies.

Linux Notes (without RPM)

If you are using Debian, Gentoo, or a non-RPM-based Linux distribution, use your distro-specific packaging mechanism such as apt-get on Debian or emerge on Gentoo.

It is also possible to install OpenVPN on Linux using the universal ./configure method. First expand the .tar.gz file:

tar xfz openvpn-[version].tar.gz

Then cd to the top-level directory and type:

./configure
make
make install

Once the openvpn package is fetched from the Internet and installed, run the client with the –version argument to make sure that it is version 2.1 or above:

openvpn --version

OpenVPN 2.1_rc15e x86_64-unknown-linux-gnu […]
[…]

Running the OpenVPN client with the downloaded client config file:

Usually, the easiest way to install an OpenVPN client is to use the --config argument to specify the location of the downloaded client config file, (Where “client” is your username!):

openvpn --config /path/to/client.ovpn

You may need to run this command using sudo.

(Ubuntu)
If you can successfully connect from command line then try adding yourself to netdev group and uncheck “Available to all users” in vpn settings window in NetworkManager and then try connecting using NetworkManager.

You can add user to ‘netdev’ group using following command

sudo usermod -aG netdev

Caveats:

When a Linux/Unix client is used with Access Server, the Access Server is unable to alter the DNS settings on the client in question.